Marathon Aid Station Strategy: When to Drink, When to Take Energy Gels

Introduction

“Hitting the Wall” is a marathon runner’s worst nightmare—around the 30–35 km mark, muscle glycogen is depleted, pace drops sharply, and the legs feel as if they are filled with lead. Many runners believe hitting the wall is an unavoidable fate, but in fact, a proper fueling strategy can significantly delay or even completely prevent it. The key lies in understanding the body’s energy metabolism and replenishing at the right moments.

Energy Metabolism Basics: Why Do You Need Fueling?

During a marathon, the body primarily uses two fuel sources:

• Glycogen (sugar): Stored in muscles and the liver, about 1600–2000 kcal, and is the main fuel for high-intensity exercise
• Fat: Nearly unlimited in storage, but burns less efficiently and can only be used in large amounts at low intensity

When pacing at a Sub-4 level, the body uses about 60–70% glycogen, which means that without replenishment, glycogen will be depleted after 2.5–3 hours. The purpose of fueling is to continuously “top up” external sugar during the race, slowing down the rate of glycogen depletion.

Hydration Timing and Amount

Hydration is the aspect most often mishandled on the course. Dehydration affects blood circulation efficiency, increases heart rate, and slows pace; but overhydration can lead to hyponatremia, which can be life-threatening in severe cases.

Hydration tips:

• Drinking while running can easily cause choking; slow down slightly or stop for 3–5 seconds to finish drinking
• Pinching the paper cup into a “∪” shape makes it easier to drink without spilling
• If sponges or cold water are available on site, use them to pour over your head to cool down (do not drink)

Energy Gel Usage Strategy

Energy gels are the most commonly used fuel among modern marathon runners, with each packet containing about 20–25 grams of carbohydrates (80–100 kcal). The correct usage strategy:

Timing:

• First gel: At the 40–45 minute mark (about 7–9K)—start replenishing before glycogen is depleted for maximum efficiency
• Subsequent gels: One every 40–45 minutes, about 4–5 gels total (depending on race duration)
• Last gel: About 10–12K from the finish line, take the final one

Pairing with water:

• After each gel, you must drink 150–200ml of water (about half a cup) to help the sugar absorb quickly
• Do not take it with sports drinks simultaneously; the double sugar load may cause gastrointestinal discomfort

Selection principles:

• Be sure to test the brand you use during training; never try it for the first time on race day
• Pay attention to caffeine content; gels with caffeine are recommended for the latter half of the race, as taking them too early may cause stomach discomfort

Electrolyte Replenishment

Marathon events in Taiwan are mostly held in autumn and winter, but even in cool weather, runners still sweat heavily and lose electrolytes (sodium, potassium, magnesium), leading to muscle cramps and accelerated fatigue.

The importance of sodium: Sodium is the electrolyte lost most in sweat, with about 500–1000mg of sodium per hour of sweating. Here are replenishment recommendations:

• Carry salt tabs, taking one every 1–1.5 hours with water
• Choose sports drinks containing electrolytes rather than plain water
• If the race provides plum powder or salty foods, consume them in moderation

Timing for Solid Foods During the Race

A hallmark of local Taiwanese races is the abundant solid food offerings, such as bananas, candies, braised eggs, and pineapple. These foods are suitable for:

• The 20–30K segment: The body’s craving for real food increases; the potassium and natural sugars in bananas are helpful during this stretch
• After 30K: Consume in small amounts; do not force yourself to eat, to avoid overburdening the stomach
• Avoid throughout: High-fiber foods (such as raw vegetables), fried foods, and dairy products

Practical Tips

• Create a “fueling plan chart”: Mark the timing and content of each replenishment by mileage, and do not rely on in-the-moment decisions on race day
• Carry your own fuel in a small waist pack or vest; do not rely entirely on what the race provides
• Aid stations are usually on the right side; move to the right early to avoid cutting across the road abruptly
• Do not toss empty cups into the middle of the road after drinking; set them down at the roadside or throw them into a trash bin

Conclusion

Fueling strategy may seem trivial, but it is one of the most critical factors in maintaining pace in the latter half of a marathon. By building fueling habits during training, testing different brands of energy gels, and executing your plan on race day, you can make “hitting the wall” someone else’s story rather than your race-day memory.

Related Reading

• Marathon Aid Station Strategy: The Art of Allocating Water, Sports Drinks, and Energy Gels
• The Impact of Marathon Fueling Strategy on Finish Time: The Rhythm of Energy Gel Intake After 30km
• Marathon Fueling Strategy: Fluid and Energy Intake During the Race
• Marathon Aid Station Food Choices: How to Refuel Without Stopping